CONCORD, N.C. — As Jimmie Johnson crossed the finish line at Saturday night's Bank of America 500, he unleashed a string of expletives to express frustration over a late-race caution which seemingly cost him the win.

Johnson was dominating the Charlotte Motor Speedway race and on his way to taking the Chase for the Sprint Cup points lead when, with 26 laps to go, NASCAR called for a debris caution and changed the complexion of the race.

On the ensuing pit stop, Johnson came out third when the cars in front of him opted for two tires instead of four. He then had a shaky restart, lost some track position and ultimately finished fourth.

So what was his biggest challenge on Saturday night?

"Debris," he said. "A debris caution."

And what was the debris in question?

"Show me," Johnson said. "I don't know. I'm being a smartass, but I don't know where it was or what it was. I didn't see anything myself."

But was the debris caution bogus or legitimate?

"I don't know, honestly," Johnson said. "I've thrown (NASCAR officials) under the bus before and it turned out there was something there, so I've just got to watch myself and watch the video and see for myself."

Johnson might be disappointed when he watches the replay. ABC didn't show the debris during its broadcast of the race.

Whatever the reason for the caution, it was potentially an eight-point swing in a tight points race (three more positions, three bonus points for a win, one less point for Kenseth and a bonus point for the most laps led). Instead, Matt Kenseth retained a four-point lead over Johnson at the halfway point of the Chase.

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"To have a debris caution stop the race when you're up there controlling it and having a good thing going is awfully frustrating," Johnson said. "We'll take the fourth. It's not the end of the world, but every point matters right now. I hate seeing something like that shake things up."

Kenseth said he didn't see the debris but also said it wasn't his focus during that part of the race.

"I didn't really look for it, so I don't know," Kenseth said. "Obviously with Jimmie dominating and he didn't get the win, he's going to think about it more."

Of course, it all might have been different had Johnson been able to restart on the front row — "a big game-changer," he said. But Hendrick Motorsports teammates Kasey Kahne and Jeff Gordon both beat him off pit road and Johnson wasn't in the favorable position.

"That would have been a different scenario," Johnson said. "Four (points) back isn't bad. I want to keep closing in on (Kenseth). Next week (at Talladega Superspeedway) is really the big one to stir things up. So we'll see how we come out of Talladega and race from there."

Jimmie Johnson was honored for his Sprint Cup championship by President Obama at the White House on Aug. 19, 2009. Johnson was previously feted by former President George W. Bush.
Andrew Harrer, Bloomberg

Jimmie Johnson, right, and crew chief Chad Knaus kiss the bricks at Indianapolis Motor Speedway after winning the Allstate 400 at the Brickyard in 2008. Johnson has four career wins at the Brickyard.
Geoff Burke, Getty Images for NASCAR

Jimmie Johnson shares a laugh with Congresswoman Nancy Pelosi, then Speaker of the House, during a visit to Capitol Hill on Feb. 5, 2007. A reporter asked if he was a Democrat or Republican. The Speaker changed the subject.
Tim Dillon, USA TODAY Sports